1. Field of the Invention
The present invention relates to a boosting voltage control circuit, and more particularly, to a boosting voltage control circuit capable of supplying a constant voltage to word lines upon a read operation in the flash memory.
2. Background of the Related Art
In a flash memory device of a low power supply voltage, voltage boosting is performed in order to boost a word line gate voltage of the cell every time the read operation of the cell is performed. In other words, boosting is to boost a low power supply voltage (VCC) to a voltage level that could be used for the read operation. Generally, the boosting operation raises a voltage of 0V to 5.3V if a read command is inputted from the outside. However, in raising the voltage from 0V to 5.3V, lots of time is taken due to various delay components such as a RC delay, etc. within the boosting circuit.
Accordingly, the present invention is contrived to substantially obviate one or more problems due to limitations and disadvantages of the related art, and an object of the present invention is to provide a boosting voltage control circuit capable of improving the speed of a read operation and minimizing the current flowing in a standby state, by keeping a voltage of a constant level in the standby state as well as the read operation
Additional advantages, objects, and features of the invention will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention. The objectives and other advantages of the invention may be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.
To achieve these objects and other advantages and in accordance with the purpose of the invention, as embodied and broadly described herein, a boosting voltage control circuit according to the present invention is characterized in that it comprises, in order to constantly keep a level of a voltage boosted by a pump, a boosting voltage dividing means for dropping a boosting voltage, a package voltage generating means for generating package voltage signals of various voltage levels depending on external trim bits, a compare reference voltage generating means for generating a reference voltage and a control voltage according to the package voltage signal from the package voltage generating means, a compare means driven by a control voltage, for comparing the dropped boosting voltage and the reference voltage to output a compare result signal, an output means for outputting first and second clock control signals using the compare result signal from the compare means, a clock generator for generating clock signals according to the first and second clock control signals, and a first pump for always outputting the boosting voltage according to the clock signal and a second pump for outputting the boosting voltage according to an external read signal and the clock signal.
Further, a boosting voltage control circuit having a pump for transferring a pumped voltage, as an output, according to the output signal of a clock generator, and a regulation block for detecting a voltage of the output to control the clock generator according to the present invention is characterized in that the regulation block comprises a boosting voltage dividing means for dropping a voltage of the output to a given level, a package voltage generating means for generating package voltage signals of various voltage levels according to external trim bits, a compare reference voltage generating means for generating a reference voltage and a control voltage according to the package voltage signal, and a compare means for comparing the output of the voltage dividing means and the reference voltage according to the control voltage to generate a control signal for controlling the clock generator.
In another aspect of the present invention, it is to be understood that both the foregoing general description and the following detailed description of the present invention are exemplary and explanatory and are intended to provide further explanation of the invention as claimed.